Djokovic, who improved to a 23-5 match record at Melbourne Park, has dropped one set in five matches at the Grand Slam championship this year. The Serbian has now won all five of his hard-court meetings with Berdych, who won their Wimbledon semi-final last year.

"I have to be very happy with the performance," said Djokovic. "Maybe the turning point was the tie-break in the second set where it went my way. If it's one-set all, it's a totally different match. Two sets up, it's a big advantage and I was starting to go for shots more in the third.

"I was physically prepared, mentally motivated to [have] some success. So far it's been great. Today has been a real test. I have nothing to lose playing Federer, who's the title defender here. We all know everything about him. I have to believe in myself in order to win that match."

Djokovic's forehand was particularly potent at the start of his sixth meeting with Berdych. He broke Berdych's serve with a forehand pass for a 3-1 lead and went onto close out the 36-minute opener with another forehand winner.

The 25-year-old Berdych saved two break points with big serves in the first game of the second set, then capitalised on a mental lapse from Djokovic. Converting the first of three break point opportunities with a forehand winner, Berdych took a 3-1 lead. Djokovic immediately broke back, hitting a forehand lob from the baseline.

As rain started to fall, the Rod Laver Arena roof was closed and the set went to a tie-break. Djokovic raced into a 5-2 lead, only for Berdych to fight back to 5-5. When a net cord bounced wide, Djokovic took a two sets to love lead and when he produced a couple of fine returns on his way to breaking at 2-1 in the third set it spelled the end of Berdych's challenge.

"I can be disappointed with the second set," said World No. 6 Berdych, who committed 32 unforced errors. "I took over a little bit and was playing well. Then, [I] just lost the set very close in the tie-break where [he] was also a bit lucky. The other two sets he was dominating and he was playing really well today."

Djokovic and Federer met in the 2008 Australian Open semi-finals en route to Djokovic lifting his only Grand Slam championship trophy. Federer leads Djokovic 13-6 overall and the Swiss has won the past three meetings. In September last year, Djokovic saved two match points against Federer in the US Open semi-finals.

Looking ahead to the semi-final match-up, Berdych said: "He's going to play Roger next match, and that's always tough. I think that Roger is really on the top form and playing really well."